User blog comment:LegionZero/Nero's Parallels to Vergil and Sparda/@comment-11462520-20140910173627/@comment-6769189-20150107045753

http://www.wired.com/2007/10/interview-hiroy/

Find an interview taking place after that date that says otherwise. Until then, thats what they finally decided was the story.

There is also more evidence against Nero being either of their son.